Bridge scaffold



United States Patent [72] Inventors Tom D. Gentry 3,035,659 /1962 Sims 182/63 922 Iowa; 3,076.522 2/1963 Goodell 182/36 J rry D. Holliday, 319 N. 6th t, 3,282,377 11/1966 Pfeiffer 182/36 Neodesha, Kans- 66757 3,394,776 7/1968 Abrams 182/ 1 50 [2!] p 780087 Primary Examiner-Reinaldo P. Machado [22] Wed 1968 Attorney-Dan M. Bradley Patented Dec. 29, 1970 [54] g gg f ggtgf g g ABSTRACT: A mobile bridge scaffold comprising an elonm g gated frame spanning a bridge transversely thereacross, a stan- [52] US. Cl 182/36, dard arried by the frame at each end thereof and depending 182/63, l82/ 150 therefrom in outwardly spaced relationship from the sides of [51] Int. Cl E04g 3/14 h bridge, and elongated platforms shiftably carried by the Field ofSearch 182/63, 36, lowermost ends of each tandard for movement from eantil- 150, 141 evered positions projecting toward the other platform beneath the bridge to provide a support for workmen, to alternate can- [56] References C'ted tilevered positions projecting outwardly away from the bridge UNITED STATES PATENTS to provide clearance to permit movement of the scaffold lon- 2,639,950 5/ 1953 Wheeler 182/37 gitudinally of the bridge.

0 30 so 66 I 108 I 2. u so :08 IO 32 84 32 3a 46 26 l 28 I2 60 56 46 i 38 I 54 34 54 I 58 10 8.

4| M a g 20 a I 20 a 2. 4a 84 2 l w 86 i 68 78 66 70 L92 00 as 70 9? 72 70 l I z '72 i v PATENTEDnmzemm 3 55 7 SHEET 2 BF 2 IIIIIIP'IHI 2 32 JHHHIIHHII" INVENTORS. Tom 0. Glenn};

Jerry 0. H01 II BY wmwqw A RNEYS.

BRIDGE SCAEFOLD This invention relates to scaffolds and, more particularly, to a movable scaffold or buggy to support workmen requiring access to the bridge, as, for example, during construction thereof. It is common practice to form bridge decks, fascia and the like from concrete which is poured into forms supported by the bridge girders. The forms and associated hardware are later stripped from the cured concrete.

The piers which support the girders have heretofore presented an obstacle to the longitudinal movement of scaffolding along the bridge, thereby rendering the construction of scaffolds for placement and removal of the bridge forms a relatively slow, expensive operation.

It is, therefore, a primary object of this invention to provide a mobile scaffold which afi'ords reasonable access around the bridge girders, yet which may be readily moved longitudinally of the bridge.

Another important object of the invention is to provide novel, cantilevered workman-supporting platforms which may be quickly and easily shifted to positions clearing the girder supports to permit movement of the scaffold longitudinally along the bridge.

Still another object of the present invention is the provision of platform support structure wherein the platforms may be turned longitudinally of the bridge to permit access to relatively long stretches of the bridge without need for moving the scaffold frame longitudinally of the bridge.

A further object of the invention is to provide a novel scaffold which may be quickly and easily adjusted to accommodate structures of various sizes.

A yet further object of the invention is to provide an easily transportable, highly versatile scaffold having auxiliary hoist means for lifting material and for shifting the scaffold components into proper position for movement from one position to another.

These and other objects of the invention will be further explained or will become apparent from the description, claims and drawings.

In the drawings: 1

FIG. 1 is a fragmentary, side elevational view on a reduced scale of a scaffold embodying the principles of this invention, a bridge being shown in vertical cross section; I

FIG. 2 is a detailed cross-sectional view taken along irregular line 2-2 of FIG'. 1;

FIG. 3 is a detailed cross-sectional view taken along irregular line 3-3 of FIG. 1;

FIG. 4 is a fragmentary, detailed cross-sectional view taken along line 4-4 of FIG. 3;

FIG. 5 is an enlarged, fragmentary,detailed vertical crosssectional view through one of the workman-supporting platforms and corresponding standard showing the connection of the rollers with the platform rail;

FIG. 6 is a fragmentary, side elevational view of one standard showing a platform supported thereby in an alternate position extending longitudinally of the bridge;

FIG. 7 is an enlarged, fragmentary, detailed cross-sectional view through the platform of FIG. 6' and illustrating the connectors used to support the platform in said alternate position;

FIG. 8 is a detailed. cross-sectional view taken along line 8-8 of FIG. 1, the position of an optional beam rider bracket appearing fragmentarily in dash linesiand FIG. 9 is an enlarged, fragmentary, vertical cross-sectional view through a leg of the scaffold frame illustrating the optional beam rider attachment.

Apparatus embodying the principles of this invention is broadly designated by'the reference numeral 10 and includes an elongated, rigid frame 12 extending transversely across a bridge 14 with the opposed ends of frame 12 projecting outwardly from the sides of the bridge. Support means 16 includ- A pair of depending standards 20 are secured at respective ends of frame 12 as illustrated best in FIG. 1. The standards 20 extend downwardly in'outwardly spaced relationship from the sides of the bridge and project substantially below the bridge girders 22. Each standard 20 carries an elongated platform 24 adapted to support workmen to provide them with access to bridge 14 as will be hereinafter explained.

Frame 12 includes a pair of parallel, horizontally spaced channel members 26 extending transversely of bridge 14. As illustrated in FIG. 1, each member 26 may comprise two or more longitudinally aligned sections interconnected by a coupler 28 so that the length of the members 26 may be selectively varied to accommodate bridges of differing widths.

The spaced channel members 26 are rigidly interconnected with transversely extending, rigid beams 30 disposed at spaced intervals along frame 12. A beam 32 is disposed in parallel relationship with channel members 26 intermediate the latter to provide a trolley rail for a hoist 34 having a trolley 36 engaged. on beam 32 for shifting movement therealong. Manifestly, beam 32 is carried by crossbeams 30 and beam 32 projects outwardly beyond the ends of frame 12 for a substantial distance as shown clearly in FIG. 1.

The support means 16 comprises a pair of vertically extending legs 38 interconnected at their, lowermost ends with a beam 40 disposed to extend generally longitudinally of bridge 14. Wheel and axle assemblies 18 are mounted at opposite ends of beam 40 and the support means is stabilized by diagonally extending braces 42 connecting beam 40 with legs 38 as'shown in FIG. 2. The uppermost ends of legs 38 are connected in back-to-back relationship to the corresponding members 26. The members 44 are thus in a position to carry crossbeams 30 for supporting the weight of frame 12. Diagonal braces 46 connect legs 38 with members 26 to stabilize support means 16 in the direction of alignment of members 26.

Each standard 20 includes a pair of parallel, spaced-apart channel members 48 as is perhaps best illustrated in FIG. 3. The spaced, parallel flanges 50 of members 48 extend toward the corresponding flanges of the opposite member 48, and the flanges 50 carry parallel, vertically spaced, rigid members 52 to present ladder means extending the lengths of the members 48. Manifestly, either oneor both of the members 48 for each standard 20 can be provided with members 52 to provide ladder means. Members 48 are also provided with a series of vertically spaced holes 54 as shown in FIG. I. The holes 54 cooperate with pin means 56 carried by the members 26 to permit vertical adjustment of the standard 20 as may be desired to accommodate the particular bridgewith which apparatus10 is used. Braces 58 and 60 interconnect members 48 of standards 20 with corresponding legs 38 of support means 16 (FIG. 1) whereby the standards are maintained in substantially upright position at all times.

pair of beams 68. The beams project outwardly beyond the respective members 48 and each end has secured thereto a depending bracket 72. Spaced-apart'rollers 74 (FIGS. 3 and 5) frame 78 and interconnecting supporting trusswork 80 as illusing wheel and axle assemblies 18 are disposed in spaced relatrated clearly in the drawings. A deck 82 which may be constructed from plywood or the like is supported on frame 78 to provide a supporting surface for workmen requiring access to Referring particularly to FIG. 1, it may be seen that each standard 20 is secured to its respective beam 68 in closer proximity to one end of the beam than the other. Diagonal braces 84 and 86 connect the ends of beams 68 to their respective members 48 for stabilizing the standards.

The rectangular, tubular box members 76 carried by platform 24 provide a rail shiftable between the sets of rollers 74 to permit longitudinal shifting of the platforms 24 from the position thereof illustrated in FIG. 1 to positions with the platforms extending outwardly completely beyond the outermost edges of bridge 14 to permit longitudinal movement of apparatus along the bridge without the platforms 24 interfering with supporting bridge structure (not shown). It is to be noted that the standards carry the platforms 24 in cantilevered relationship irrespective of whether or not the platforms are in the positions shown or in the positions projecting outwardly for clearing the bridge support structure.

The platforms 24, when in the positions thereof illustrated in FIG. 1, may be releasably interconnected by a lock 88. Any suitable lock may be utilized for this purpose and it is not deemed necessary to describe lock 88 in greater detail.

There is preferably a hoist 34 for each end of I-beam 32. When it is desired to move a platform 24 to its outwardly projecting position, an elongated, flexible element 90, such as a cable or the like, is secured to the inwardly projecting end of the platform, is threaded through pulley means 92 on standard 20, and is engaged with the hoist means 34. A workman operating the hoist can quickly and easily shift the platform 24 to the outwardly projecting position to permit longitudinal movement of apparatus 10.

Conversely, when it is desired to move the platforms to the workman-supporting position to provide the workman with access to the bridge 14 transversely of the latter, the element 90 is secured to the outermost projecting end of platform 24. Pulley means 92 may be repositioned to the outermost side of the standard 20 whereupon pulling of the element 90 by hoist 34 shifts the rails and, therefore, the platform, along rollers 74, to the position thereof illustrated in FIG. 1. The platforms 24 are then secured together by latch means 88 whereupon the workman may move along deck 82 as may be required for performing necessary operations in and around bridge 14.

Hoists 34, when not utilized for shifting platforms 24, may be used to move material toward and away from the deck 82. Accordingly, apparatus 10 is particularly useful as a stripping buggy for removal or placement of concrete forms used in the construction of the fascia and roadway of the bridge. It will be readily recognized that pulley means 92 for each position relative to standard 20 illustrated in FIG. I may be secured to the standard at all times to obviate the necessity for changing the positions of the pulley means.

When it is desired to utilize apparatus 10 for supporting workmen alongside the bridge 14 rather than beneath the latter, the standards 20 may be utilized for carrying the platforms 24 in positions extending longitudinally of the bridge. For such operations, the beams 70 and brackets 72 are removed from the standards. The platforms 24 are rotated 90 with respect to the positions illustrated in FIGS. 1, 3 and 5. U- shaped bolts 94 are then utilized to secure rails 76 directly to beams 68 as is illustrated in FIGS. 6 and 7. It will be appreciated that workmen may then walk along deck 82 and the apparatus 10 can be moved longitudinally of the bridge to permit workmen access to relatively long stretches of the bridge.

The positional relationship of the members 48 with respect to the beams 68 permit the supporting of the platforms 24 in greater proximity to the edges of bridge 14 than that illustrated in the drawing simply by reversing the direction in which the standards 20 face. In other words, if the standards 20 are turned around, the longest portion of beam 68 projectiing from members 48 is directed inwardly toward the bridge. This, in turn, moves the position of support of the platforms 24 inwardly. The workmen are thus moved closer to the bridge when such disposition for the workmen is desired.

Although apparatus 10 is particularly useful for removing forms used in constructing bridge 14, it can be used in placing the forms and for other operations prior to pouring of the concrete. To this end, it is but necessary to augment the wheel and axle assemblies 18 with beam rider structure broadly designated 96 illustrated particularly in FIG. 9.'Structure 96 includes a beam 98 adapted to be releasably secured to the beams 40 which mount the assemblies 18. To this end, one or more U-bolts 100 releasably clamp beam 98 to beams 40 as illustrated in FIG. 9.

Depending legs 102 have their uppermost ends secured at spaced-apart intervals along beam 98, and a roller 104 is mounted on each leg 102 for rotation about vertical axes. Diagonally extending turnbuckle means 106 may be secured to legs 102 and beam 98 to stabilize the assembly. The spacing between rollers 104 is such that the rollers engage the outer most longitudinal edges of the uppermost flange of a corresponding bridge girder 22. The wheel and axle assembly 18 is supported by the flange of girder 22 so that apparatus 10 is supported by the girders and may be moved longitudinally thereof without necessity for the roadway and without danger of the frame 12 falling from its supporting girders.

Apparatus 10 is particularly well suited for easy transportability from one bridge construction site to another. To transport apparatus 10, the platforms 24 are shifted outwardly to the positions thereof as if the apparatus 10 were to be moved around a bridge-supporting pier. A crane on bridge 14 is then secured to apparatus 10 by means of pickup eyes 108 (FIG. 1) on member 26. The crane lifts the entire apparatus 10 until the platforms 24 will clear the top of bridge deck 14. The crane then rotates the entire apparatus approximately and brings it to a position over the top of deck 14. Platforms 24 are then shifted inwardly to their closed positions whereupon lock 88 is secured. The crane then sets the entire apparatus down upon a vehicle such as a low-boy or the like. Attachment of members 26 and S8 to members 48 is then released to permit the crane to lower the upper portion of the structure down until wheel trucks l8 engage the decks 82.

When properly positioned for transport, the wheel and axle assemblies 18 will rest upon the deck 82 of each platform. The upwardly extending members of each standard 20 may be constructed in sections so that the vertical height of the apparatus 10 may be minimized to enhance transportability.

We claim:

1. A mobile scaffold for supporting workmen adjacent a bridge, said scaffold comprising:

a frame adapted to extend transversely across said bridge,

the frame including support means adapted to engage the bridge and to permit movement of the frame longitudinally of the bridge;

a standard for each end of the frame respectively, each standard being carried by the frame and extending downwardly therefrom, the standards being adapted to extend downwardly below the girders of said bridge and in outwardly spaced relationship from the corresponding sides of thebridges;

an elongated platform for each standard respectively;

means mounting each platform to its corresponding standard for movement between a first position projecting inwardly beneath the bridge girders and toward the other platform, to a second position disposed outwardly from the corresponding edges of the bridge to permit movement of the scaffold longitudinally of the latter; and a trolley extending longitudinally of the frame, and hoist means carried by the trolley for movement therealong to any selected lifting position.

2. A mobile scaffold for supporting workmen adjacent a bridge, said scaffold comprising:

a frame adapted to extend transversely across said bridge, the frame including support means adapted to engage the bridge and to permit movement of the frame longitudinally of the bridge;

a standard for each end of the frame respectively, each standard being carried by the frame and extending downwardly therefrom, the standards being adapted to extend downwardly below the girders of said bridge and in outwardly spaced relationship from the corresponding sides of the bridge; i

an elongated platform for each standard respectively;

means mounting each platform to its corresponding standard for movement between a first position projecting inwardly beneath the bridge girders and toward the other platform, to a second position disposed outwardly from the corresponding edges of the bridge to permit movement of the scaffold longitudinally of the latter; and

said mounting means including a pair of rollers carried by the standard and a rail carried by the platform, said rollers being engageable with the rail to carry the weight of the platform and to facilitate manual shifting of the platform between said first and second positions, said rail extending longitudinally of the platform and the rollers being disposed to engage the rail intermediate the ends of the platform, and wherein is included pulley means secured to the standard proximal the lowermost end thereof, and a flexible element having one end thereof secured to one end of the platformand extending through the pulley means whereby to shift the platform along the rollers when a pulling force is exerted on the other end of the element.

3. A mobile scaffold for supporting workmen adjacent a bridge, said scaffold comprising:

a frame adapted to extend transversely across said bridge, the frame including support means adapted to engage the bridge and to permit movement of the frame longitudinally of the bridge; a standard for each end of the frame respectively, each standard being carried by the frame and extending downwardly therefrom, the standards being adapted to extend downwardly below the girders of said bridge and in outwardly spaced relationship from the corresponding sides of the bridge; I

an elongated platform for each standard respectively;

means mounting each platform to its corresponding standard for movement between a first position projecting inwardly beneath the bridge girders and toward the other platform, to a second position disposed outwardly from the corresponding edges of the bridge to permit movement of the scaffold longitudinally of the latter;

said mounting means including a pair of rollers carried by the standard and a rail carried by the platform, said roller means being engageable with the rail to carry the weight of the platfonn and to facilitate manual shifting of the platform between said first and second positions,

the standard including an upright, a crossmember secured to the lowermost end of the upright at a point along the crossmember closer to one end than the other end thereof, one of said rollers being carried at each end of said crossmember respectively; and

means releasably mounting the upright to the standard with either of said ends of the crossmember projecting toward the other standard, the relative position of said platforms with respect to the sides of the bridge being varied in accordance with which of said ends of the crossmember is projecting toward the other standard. 

